1. Field of the Invention
The present invention relates to an editing apparatus and an editing method of video data, and more specifically, to an editing apparatus and an editing method for editing system streams and program streams of an MPEG standard.
2. Description of the Related Art
In recent years, MPEG (Moving Picture Experts Group) as an audio/video recording digital format has been used widely. The MPEG standard, along the expansion of its applications and the release of new compression technologies, has had some versions, and those used mainly at present are MPEG-1, MPEG-2 and MPEG-4. There are many hardware items for encoding audio/video data into these MPEG data.
In the MPEG standard, besides specifications of video compressed data (VideoElementaryStream, hereinafter referred to as VideoES), and audio compressed data (AudioElementaryStream, hereinafter referred to as AudioES), the multiplexing methods for playing these compressed video and audio data in synchronization are specified. Specifications corresponds to these are MPEG1SystemStream (hereinafter, MPEG-1 SS) in MPEG-1, and MPEG2ProgramStream (hereinafter, MPEG-2 PS) in MPEG-2. These two specifications are structured by similar syntax, but there is no complete compatibility therebetween.
Meanwhile, MPEG-2 encoders released recently have functions to encode VideoES and AudioES as MPEG-1 stream data, however, with regard to the multiplexing methods, many of them do not cope with MPEG-1 SS, but cope with only MPEG-2 PS. On the other hand, among software programs capable of reproducing MPEG data on personal computers, there are many that cope with only MPEG-1 format, therefore they cannot play MPEG-2 PS data encoded by such MPEG-2 encoders as the above, which has been a problem in the prior art.
In a conventional information recording device that converts formats of information, when recording a video stream whose format may be converted, conversion information necessary at format conversion is inserted into recording information in advance, thereby the calculation amount at conversion is reduced and conversion in a realistic time period is enabled (for example, refer to Japanese Patent KOKAI Publication No. 2003-151215, paragraphs [0003] and [0005]).
However, the above document handles with conversion of data streams based on a DVD-VR (Video Recording) standard into a DVD-V (Video) standard that has no compatibility therewith, and does not handle with conversion in the MPEG standard.
As described above, there has been the problem that MPEG-2 PS data encoded by the conventional MPEG-2 encoders cannot be played back by software programs that operate on personal computers and cope with only MPEG-1 format.